Following is dump of style.ini in /tpl/roundbox/ directory.
If I change the __theme__ parameter
manually in this file to match my requirement the error is not appearing.
; Please see http://www.php.net/manual/en/function.parse-ini-file.php
; for limitations of the ini format used here
; Define the stylesheets your template uses here. The second value
; defines for which output media the style should be loaded. Currently
; print, screen and rtl are supported. rtl styles are loaded additionally
; to screen styles if a right-to-left language is selected (eg. hebrew)
[stylesheets]
layout.css = screen
design.css = screen
style.css = screen
media.css = screen
UWEB.css = screen
rtl.css = rtl
print.css = print
sidebar.css = screen
; This section is used to configure some placeholder values used in
; the stylesheets. Changing this file is the simplest method to
; give your wiki a new look.
[replacements]
; the theme name
__theme__ = "evening"
;--------------------------------------------------------------------------
;------ guaranteed dokuwiki color placeholders that every plugin can use
; main text and background colors
__text__ = "#9cc"
__background__ = "#357"
; alternative text and background colors
__text_alt__ = "#aee"
__background_alt__ = "#135"
; neutral text and background colors
__text_neu__ = "#000"
__background_neu__ = "#dee"
; border color
__border__ = "#000"
;--------------------------------------------------------------------------
; other text and background colors
__text_other__ = "#bbc"
__background_other__ = "#433"
;__text_other__ = "#433"
;__background_other__ = "#dee"
; border color
__border_alt__ = "#8ab"
; these are used for links
__extern__ = "#999"
__existing__ = "#797"
__missing__ = "#d33"
; highlighting search snippets
__highlight__ = "#ff9"
;--------------------------------------------------------------------------
;------ for keeping old templates and plugins compatible to the old pattern
; (to be deleted at the next or after next release)
__white__ = "#fff"
__lightgray__ = "#f5f5f5"
__mediumgray__ = "#ccc"
__darkgray__ = "#666"
__black__ = "#000"
; these are the shades of blue
__lighter__ = "#f7f9fa"
__light__ = "#eef3f8"
__medium__ = "#dee7ec"
__dark__ = "#8cacbb"
__darker__ = "#638c9c"
[/color]